Transpyloric anchoring

ABSTRACT

A gastrointestinal implant device ( 2800 ) comprises a planar proximal element ( 220 ) configured to reside in a stomach to resist distal migration, a distal element ( 222 ) configured to reside in an intestine to resist proximal migration and one or more tethers ( 224 ) coupling the planar proximal element to the distal element.

RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.61/671,470, filed on Jul. 13, 2012. The entire teachings of the aboveapplication are incorporated herein by reference.

BACKGROUND OF THE INVENTION

There is an ongoing need to improve the duration of time over whichgastrointestinal implants may safely be anchored in the gastrointestinaltract without occlusion, migration or other malfunction or drawbacks,particularly for implants that extend over at least a portion of theintestines.

Examples of such implants include those having flexible (floppy) sleevesextending into the intestine such as presented in U.S. Pat. Nos.7,025,791; 7,122,058; 7,476,256; 7,608,114; 7,706,973; 7,771,382;7,815,589; 7,837,643; 8,057,420; and those having restrictive orificesas presented in U.S. Pat. No. 7,771,382. All of those patents areincorporated by reference in their entirety.

SUMMARY OF THE INVENTION

In accordance with an embodiment of the invention, there is provided agastrointestinal implant device. The device comprises a planar proximalelement configured to reside in a stomach to resist distal migration; adistal element configured to reside in an intestine to resist proximalmigration; and one or more tethers coupling the planar proximal elementto the distal element. A single tether is generally preferred.

The distal element may be configured to seal to tissue of the intestine,thereby channeling chyme from the stomach into the intestine. The planarproximal element may comprise a hoop. The distal element may comprise awave anchor. The planar proximal element may be significantly largerthan a diameter ofa pylorus of the stomach in a first dimension, and maybe smaller than the diameter of the pylorus in a second dimension,orthogonal to the first dimension. The planar proximal element may bebetween about 40 mm and about 100 mm in size in the first dimension;such as between about 50 mm and about 100 mm in size in the firstdimension. The planar proximal element may be between about 1 mm andabout 15 mm in size in the second dimension; for example, between about1 mm and about 5 mm in size in the second dimension. The planar proximalelement may comprise a hoop of between about 40 mm and about 60 mmdiameter and of between about 0.5 mm and about 5 mm in thickness. Thetether may comprise a flexible tether or a rigid tether. The planarproximal element may comprise a circular, polygon or an ellipsoid shape.The proximal element may be planar; for example, it may comprise atleast one member of the group consisting of: a hoop, a polygon and anellipsoid shape.

In further, related embodiments, the device may comprise no tissuepenetrating features. The device may further comprise an unsupported,thin-walled sleeve coupled to the distal element. The sleeve may befloppy, flexible, conformable and collapsible. The planar proximalelement may be without a seal to the stomach. In normal use of theimplant device, a central longitudinal axis of the planar proximalelement, perpendicular to a plane in which the planar proximal elementlies, may be substantially perpendicular to a central longitudinal axisof a lumen of at least one of: a pyloric sphincter of the stomach; andthe intestine. The distal element may comprise a three-dimensionalobject. The distal element may comprise a restrictor; and/or afluid-filled chamber and/or a toroidal object. The distal element maycomprise at least one of a catheter and a diagnostic device. The distalelement may be between about 30 mm and about 40 mm in diameter. Thedistal element may comprise a wave anchor. The distal element maycomprise a length to diameter ratio of at least about one. The distalelement may comprise a length of between about 30 mm and about 40 mm;such as a length of at most about 32 mm, and may comprise an anchor ofabout the same length as the duodenal bulb. The distal element maycomprise a spring element.|_([A1]).

In further related embodiments, at least one of the planar proximalelement, the tether and the distal element may be covered in anatraumatic material, such as at least one of urethane and silicone. Thetether may comprise a suture made of polymer or metal. The tether may bebetween about 10 mm and about 50 mm in length, and may be between about0.5 mm and about 5 mm in diameter, such as between about 1 mm and about2 mm in diameter. The distal element may comprise a plurality of spokes,and the tether may be coupled to the plurality of spokes. The distalelement may be configured to change shape upon transmission of force tothe distal element by the tether. The distal element may comprise a waveanchor, the tether being coupled to at least one crown of the waveanchor; such as the tether being coupled to a distal crown of the waveanchor, where the wave anchor comprises a diameter of between about 30mm and about 40 mm. The distal element may be configured to openradially outwards upon exertion of tension by the tether to resistproximal migration. The planar proximal element may be loosely attachedto the tether, thereby permitting the planar proximal element to rotateindependently of the tether. The planar proximal element may be coupledto a tie loop to which the tether is coupled.

In further related embodiments, at least one of the planar proximalelement and the distal element may comprise a polymer. The polymer maycomprise at least one material of the group consisting of: silicone,polytetrafluoroethylene, polyethylene and polypropylene. At least one ofthe planar proximal element and the distal element may comprise a metal.The metal may comprise at least one of nitinol and stainless steel. Theplanar proximal element, distal element and tether may be configured tobe collapsible into a container for endoscopic delivery into agastrointestinal tract. At least one of the proximal element and thedistal element may further comprise a removal drawstring.

There is provided a method of treatment comprising: with a planarproximal element in a stomach, resisting distal migration of a proximalportion of a gastrointestinal implant device into an intestine; with adistal element in the intestine, resisting proximal migration of adistal portion of the gastrointestinal implant device into the stomach;and with one or more tethers, securing the planar proximal element tothe distal element across a pylorus. A single tether is generallypreferred.

The method may further comprise sealing the distal element to tissue ofthe intestine, thereby channeling chyme from the stomach through theduodenal element into the intestine. The method may comprise securingthe gastrointestinal implant device without penetrating tissue. Themethod may further comprise channeling chyme from the stomach into anunsupported, thin-walled sleeve extending into the intestine from thegastrointestinal implant device. The method may comprise resistingmigration of the planar proximal element into the intestine withoutsealing the planar proximal element to the stomach. In the method, innormal use of the gastrointestinal implant device, a centrallongitudinal axis of the planar proximal element, perpendicular to aplane in which the planar proximal element lies, may be aligned to besubstantially perpendicular to a central longitudinal axis of a lumen ofat least one of: a pyloric sphincter of the stomach; and the intestine.The method may comprise restricting a flow of chyme from the stomachinto the intestine using a restrictor coupled to the gastrointestinalimplant device. The method may comprise retaining an anchor portion ofthe distal element within the duodenal bulb. The distal element may beconfigured to change shape upon transmission of force to the distalelement by the tether; such as the distal element may be configured toopen radially outwards upon exertion of tension by the tether. Theplanar proximal element may be loosely attached to the tether, therebypermitting the planar proximal element to rotate independently of thetether. The method may comprise delivering the planar proximal element,distal element and tether inside a container with an endoscope into agastrointestinal tract.

There is provided a method of removing a gastrointestinal implant. Themethod comprises severing one or more tethers that couples a planarproximal element of the gastrointestinal implant in a stomach with adistal element of the gastrointestinal implant in an intestine; with acatheter, removing the planar proximal element proximally out of thestomach through a mouth; and with a grasper on a distal end of thecatheter, grasping a drawstring to remove the distal element proximallyout of the intestine, though the stomach and out of the mouth.

In further, related embodiments, removing the planar proximal elementmay comprise passing the planar proximal element through an overtube.Removing the distal element may comprise collapsing the distal elementradially into a retrieval hood.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing will be apparent from the following more particulardescription of example embodiments of the invention, as illustrated inthe accompanying drawings in which like reference characters refer tothe same parts throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingembodiments of the present invention.

FIG. 1 is a sectional view of a portion of the digestive tract in abody.

FIG. 2 is a perspective view of a gastrointestinal implant device withan embodiment of an anchoring device having a single tether and waveanchor distal element.

FIG. 3 is a sectional view of a body showing the gastrointestinalimplant device of FIG. 2 implanted in the digestive system.

FIG. 4 is gastrointestinal implant devices in accordance with anotherembodiment of the invention having a single tether and stent distalelement.

FIG. 5 is an implant device of the invention having plural tethers.

FIG. 6 is an implant device of the invention having a planar distalelement.

FIG. 7 is an implant device of the invention in which the tether iscoupled to spokes on the distal element.

DETAILED DESCRIPTION OF THE INVENTION

A description of example embodiments of the invention follows.

There is provided an anchor for a gastrointestinal implant device. Theanchor spans the pylorus, and therefore is called a transpyloric anchor.It is an objective of certain embodiments to provide the same or similarfunctionality as is provided by existing anchoring techniques forgastrointestinal implant devices, while having fewer side effects (suchas bleeding, discomfort, migration and/or infection), and while havingfew or no tissue penetrating features.

Among other things, certain embodiments provide a method and apparatusfor the application of a barrier sleeve in the digestive tract to limitthe contact of food products in specific parts of the digestive tractand to provide enhanced satiety to patients with morbid obesity,enabling them to reduce their food intake. The sleeve may also be usedfor other treatments such as Type-2 diabetes through hormone triggers.

A rationale behind a transpyloric anchor in accordance with certainembodiments is that the antrum of the stomach is an advantageouslocation for a proximal element of the anchor; the duodenal bulb is anadvantageous location for a distal element of the anchor; and thepylorus is a definite mechanical feature, which can be used foranchoring. The antrum of the stomach is adjacent to the pylorus and hastough tissue, while the duodenal bulb has minimal motion and permits thedistal anchor to seal against tissue.

In a relaxed state, the stomach becomes flat, and thus a lightweightplanar proximal element is able to orient itself in a plane within therelaxed stomach to cause as little trauma as possible to the stomach.

In accordance with certain embodiments, components of a transypyloricanchor include: (i) a planar proximal element in the stomach, whichprevents distal migration; (ii) a distal element in the intestines,which both prevents proximal migration and may provide a seal; and (iii)one or more tethers, which connects the proximal and distal element.

FIG. 1 is a sectional view of a portion of the digestive tract in abody. Food to be digested enters the stomach 102 through the cardiacorifice 110 from the esophagus. Chyme, a semi-fluid, homogeneous creamyor gruel-like material produced by gastric digestion in the stomachexits the stomach through the pyloric orifice (pylorus) 108 and entersthe small intestine 112. The pylorus 108 is a distal aperture of thestomach 102 surrounded by a strong band of circular muscle. The smallintestine, about nine feet in length, is a convoluted tube, extendingfrom the pylorus 108 to the ileo-caecal valve where it terminates in thelarge intestine. The small intestine has three sections, the duodenum104, jejunum 106 and the ileum (not shown). The first eight to ten inchsection of the small intestine 112, the duodenum 104, is the shortest,widest and most fixed part of the small intestine 112.

The duodenum 104 has four sections: superior, descending, transverse andascending which typically form a U-shape. The superior section is abouttwo inches long and ends at the neck of the gall bladder. The superiorsection also defines a feature referred to as the duodenal bulb 119 thatbegins just distal to the pylorus 108 and extends for about 1 to 1.5inches in an adult human. The duodenal bulb 119 defines a lumen thereinthat is slightly larger than the distal duodenum 104. Advantageously,the duodenal bulb 119 exhibits less motion than the pylorus 108 and evendistal portions of the duodenum 104. Notably, the motion issubstantially limited to contractions without having a significantlinear component (i.e., no movement along the central axis of theintestine). However, the tissue thins as one moves away from the pylorus108.

The descending section of the duodenum 104 is about three to four incheslong and includes a nipple shaped structure (papilla of Vater) 114through which pancreatic juice from the pancreas and bile produced bythe liver and stored by the gall bladder enter the duodenum from thepancreatic and bile ducts. The pancreatic juice contains enzymesessential to protein digestion and the bile dissolves the products offat digestion. The ascending section is about two inches long and formsthe duodenal-jejunal flexure 116 where it joins the jejunum 106, thenext section of the small intestine. The duodenal-jejunal flexure 116 isfixed to the ligament of Treitz 118 (musculus supensionus duodeni). Thejuices secreted in the duodenum break the partially digested food downinto particles small enough to be absorbed by the body. The digestivesystem is described in Gray's Anatomy (“Anatomy of the Human Body,” byHenry Gray) and “Human Physiology,” Vander, 3^(rd) ed, McGraw Hill,1980, the contents of which are incorporated herein by reference intheir entirety.

FIG. 2 is a perspective view of a gastrointestinal implant device 2800comprising an anchoring device in accordance with an embodiment of theinvention. The device 2800 comprises a planar proximal element 220configured to reside in a stomach to resist distal migration; a distalelement 222 configured to reside in an intestine to resist proximalmigration and to provide a seal; and a single tether 224 coupling theplanar proximal element 220 to the distal element 222.

In accordance with an embodiment of the invention, the planar proximalelement 220 prevents distal migration only by being large enough that itcannot fit through the pylorus 108. In addition, a lack of leading edgesinherent in this geometry makes it hard for the proximal element to pushthrough the pylorus. There is no need for the proximal element 220 toform a seal to the stomach wall, nor for it to penetrate tissue of thestomach; and indeed, forces against the tissue required for sealing andmembers that penetrate tissue are undesirable in the proximal element220 because the antrum of the stomach is a very active region thatfrequently undergoes contractions. The proximal element 220 can moverelatively freely within the stomach (subject to the tether and contactwith food and the walls of the stomach) without engaging tissue orforming a seal. By being planar, the proximal element 220 is atraumaticto the stomach tissue, since it orients in the plane of the stomach whenthe stomach is relaxed and without food and therefore typically thestomach is flat in this state. Likewise, the proximal element 220 shouldhave as little mass as possible, in order to avoid trauma. The planarproximal element 220 may, for example, be a planar hoop or ring with anempty middle, as shown in FIG. 2. The hoop or ring may have a diameterbetween about 40 mm and about 100 mm. Using a diameter too small mayrisk the proximal element 220 migrating distally through the pylorusinto the intestine; whereas using a diameter that is too large may riskproducing trauma to the stomach. In one example, the proximal elementmay be a ring of about 60 mm diameter. The proximal element 220 shouldalso be easy to deliver, which may be performed by bending the ring tofit within a container that can fit through the mouth and esophagus. Theproximal element 220 is formed of a resilient material that can bedeformed and return to its original shape. For example, the proximalelement 220 may be formed of a metal such as stainless steel or Nitinol,or a polymer, such as polyethylene, polytetrafluoroethylene,polypropylene or silicone. The proximal element 220 may also be braided,such as a braided metal or polymer. In one example, the proximal element220 is a ring of about 60 mm in diameter, formed of nitinol or stainlesssteel, coated with silicone or urethane. This could be a polymer coatingor a tube that covers the element. A ring 220 may be formed by joiningtogether nitinol components using one or more crimps 228 or by welding,and may then be covered with an atraumatic substance.

In accordance with an embodiment of the invention, the proximal element220 may be normally oriented perpendicular to the lumen of the pyloricsphincter or the intestinal lumen, as shown in FIG. 3. Morespecifically, in normal use of the implant device, a centrallongitudinal axis of the planar proximal element, perpendicular to aplane in which the planar proximal element lies, is substantiallyperpendicular to a central longitudinal axis of a lumen of pyloricsphincter of the stomach, or of the intestine. Because the proximalelement 220 moves relatively freely, subject to tension from the tetherand contact with chyme and the stomach walls, it will also be orientedat a variety of different angles in use.

While the planar proximal element 220 is described as “planar” it hassome thickness in practice. The planar proximal element is significantlylarger than a diameter of a pylorus of the stomach in a first dimension,and is smaller than the diameter of the pylorus in a second dimension,orthogonal to the first dimension. For example, the planar proximalelement may be between about 40 mm and about 100 mm in size in the firstdimension (e.g., diameter); such as between about 50 mm and about 100 mmin size in the first dimension (e.g., diameter); and between about 0.5mm and about 15 mm in size in the second dimension (e.g., thickness andbending), such as between about 1 mm and about 5 mm in size in thesecond dimension (e.g., thickness). In one example, the planar proximalelement comprises a hoop of between about 40 mm and about 60 mm diameterand of between about 1 mm and about 5 mm in thickness. The planarproximal element may comprise other planar shapes in addition to a ringor hoop, such as a polygon or an ellipsoid shape.

In accordance with an embodiment of the invention, the distal element222 has the purpose of both sealing to the tissue of the intestines, andpreventing proximal migration. By forming a seal, the distal element 222permits chyme to be channeled into the distal element without contactingthe walls of the intestines, thereby forming an intestinal bypass. Thedistal element 222 may be a three dimensional object, such as a waveanchor 2810 (shown in FIG. 2), to which an unsupported, flexible sleeve202 may be attached. The sleeve may be floppy, flexible, conformable andcollapsible. For example, the sleeve may be one taught in U.S. Pat. No.7,981,163 B1, the entire disclosure of which is hereby incorporatedherein by reference, or any of the previously cited U.S. patents. Thedistal element 222 may also be another three dimensional object, such asa balloon and/or a toroidal element, and may include a fluid-filledchamber. For example, the distal element may be a fluid-filled toroidalelement such as those taught in U.S. Patent App. No. 2011/0004228 A1 ofPriplata et al., the entire disclosure of which is hereby incorporatedherein by reference. The distal element 222 may support a restrictiveelement, such as a plate resistor, which may be combined with a sleeve.The resistor extends across the anchor or a sleeve and has one or morerestrictive apertures therein. Further, the distal element 222 maysupport a catheter or a diagnostic device, such as a pressure sensor.The diameter of the distal element 222, such as a wave anchor, may bebetween about 30 mm and 40 mm, in order to avoid trauma to theintestine. For example, the diameter may be about 35 mm. The length todiameter ratio of the distal element 222 may be about one. In length,the distal element 222 may be of about the same length as the duodenalbulb 119, in order to fit within that anatomical feature. The waveanchor may comprise a single wave of a few cycles, five being shown. Thewave may be formed of collapsible wire, such as of metal such asNitinol. The distal element 222 may include no tissue penetratingfeatures, such as barbs, and may be coated or covered with an atraumaticsubstance such as silicone or urethane.

In another embodiment according to the invention, the distal element 222may be planar. For example, the distal element may be a hoop, a polygonor an ellipsoid shape. This shape would not provide a seal, but wouldprovide atraumatic anchoring.

In accordance with an embodiment of the invention, the purpose of thetether 224 is to couple the proximal element 220 to the distal element222. Using a single tether 224 provides the advantage of avoidingtangling, as could occur if multiple tethers were to be used. The tether224 may be flexible such as a suture or may be rigid, such as a rod.Regardless of whether flexible or rigid, the tether 224 may be attachedat its proximal end to a tie loop 226, which permits the proximalelement 220 to rotate independently of the tether 224 by sliding throughloop 226. The tether 224 is between about 10 mm and about 50 mm inlength. If the tether is too short, it may force the pylorus open,causing discomfort, but if it is too long, it may permit the distalelement 222 to move too far into the intestine, such as out of theduodenal bulb. The tether has a diameter of between about 0.5 mm andabout 5 mm, such as between about 1 mm and about 2 mm. A diameter thatis too large may cause the pylorus to sense the tether. If too small, itcould cause cutting of the tissues. In one example, the tether is asuture. The tether may be attached at its distal end to the center of aset of spokes, such as spokes made of sutures, which extend to the innerperiphery of the distal element 222. The tether may, for example, beformed of polypropylene braid, or polyethylene or ptfe; and may beeither uncovered or covered, for example with silicone, ePTFE orurethane to prevent trauma.

In another embodiment, the tether 224 may be attached at its distal endto the distal element 222 in a way that causes the distal element 222 tochange its shape. For example, where the distal element 222 is a waveanchor, the tether 224 may be coupled to a distal crown of the waveanchor, which tends to cause the wave anchor to open radially outwardsat its proximal end when the tether 224 exerts tension on the distalelement 222. In this way, the distal element 222 actively resistsproximal migration. Other active elements may be used for the distalelement 222.

In the embodiment of FIG. 2, the gastrointestinal implant device 2800includes a sleeve 202 and an anchoring device 2810 for anchoring thegastrointestinal implant 2800 device in the duodenum 104. The anchoringdevice 2800 includes a wave anchor 2810 coupled to a proximal portion ofthe sleeve 202. The wave anchor 2810 includes a compliant, radial springshaped into an annular wave pattern about a central axis, providing anoutward radial force, while allowing substantial flexure about itsperimeter. Such flexure is advantageous as it may be collapsed radiallyto allow for minimally-invasive delivery and ensures that the devicewill substantially conform to the surrounding anatomical structure whenimplanted and allowed to expand. The annular wave element can be formedfrom one or more elongated resilient members and defines a lumen alongits central axis formed between two open ends.

When implanted, as shown in FIG. 3, the proximal element 220 movessubstantially freely in the stomach, while the central axis of thedistal element's anchor 2810 is substantially aligned with the centralaxis of the duodenum 104, allowing chyme to pass through the device2800. Additionally, the compliant wave anchor 2810 minimizes trauma tothe tissue by providing sufficient flexibility and compliance, whileminimizing the likelihood of tissue erosion.

The compliant wave anchor 2810 can be manufactured from a resilientmetal such as a heat-treated spring steel, stainless steel, or from analloy such as NiTi alloy commonly referred to as Nitinol. Other alloysinclude nickel-cobalt-chromium-molybdenum alloys possessing a uniquecombination of ultrahigh tensile strength, such as MP35N. Additionally,the wave anchor 2810 can be formed from a polymer and/or a compositehaving similar properties. The wave anchor 2810 can be manufactured froma single strand, such as a wire, contoured into the desired shape.Alternatively, the wave anchor 2810 can be manufactured frommulti-strands of the same or different materials similarly contoured tothe desired shape. In some embodiments, the wave anchor 2810 can be cutinto the wave shape from tubular stock of the desired material, such asNitinol.

When implanted, the anchor 2810 can enable a sleeve 202, or barrier tobe securely implanted within the duodenum 104, preferably providing afluid seal at the proximal end. To enhance a fluid seal, the proximalend of the sleeve can be contoured to the wave anchor as shown in FIG.2. For a device 2800 using a sleeve 202 contoured to the wave anchor2810, the proximal end appears tulip-shaped.

In an embodiment according to the invention, the proximal element 220may prevent the device from migrating distally, but may be without aseal, whereas the distal element 222 is used to form a seal againsttissue, such as the duodenal wall.

In one example, the distal element 222 is a 32-33 mm diameter waveanchor, with five peaks, formed from wire of 0.032-0.035 inches. Thehoop 220 may, for example, be 0.034 inches thick, formed of two loopswith two crimps; or 0.025 inches thick, formed of three loops with twocrimps.

In another example, the proximal element 220 comprises 2 loops of 0.040″diameter wire, crimped together in two spots, 180 degrees opposed, witha 60 mm diameter overall loop; while the distal element 222 comprises a35 mm diameter wave anchor, with a greater than one pound compliance andformed of 0.030″ diameter wire. A wave anchor as large as 55 mm diametermay also be used, with no tissue engaging barbs. It will be appreciatedthat a variety of different diameters, wire thicknesses, compliances andnumber of crowns for a wave anchor may be used (for example, five or sixcrowns on the wave anchor).

In FIG. 4, the distal element 222 comprises a stent 442.

FIG. 5 shows an embodiment in which the wave anchor 2810 is tetheredwith two tethers. This is less preferred for reasons expressed above butmay have some application.

FIG. 6 shows an embodiment in which the distal element 222 is alsoplanar. The planar distal element serves to retain the device againstproximal movement but does not provide fluid sealing against theintestine.

FIG. 7 shows an embodiment in which the tether is coupled to spokes 702on the distal element.

The planar proximal element, distal element and tether are configured tobe collapsible into a container for delivery through the mouth andesophagus into a gastrointestinal tract. For example, container deliverytechniques may be used such as those taught in U.S. Pat. No. 7,837,643B2 of Levine et al., the entire disclosure of which is herebyincorporated herein by reference.

In an embodiment according to the invention, the device may be removedby cutting the tether 224, and then pulling the proximal element 220(such as a hoop) through the esophagus, for example through anesophageal overtube. The proximal element 220 (such as a hoop) can becut or undone to assist in removal. Alternatively, suture material maybe used in one or more components, which may be cut to assist inremoval. The device may be able to be removed without an overtube.Further, the foregoing methods may be used to remove the proximalelement 220, while another method of removal is used for the distalelement 222, for instance using a drawstring 2810 (FIG. 3) technique asset forth in U.S. Pat. No. 8,057,420, the entire disclosure of which ishereby incorporated herein by reference. The proximal element and/or thedistal element further may comprise a removal drawstring.

In one embodiment, a method of removing a gastrointestinal implantcomprises severing one or more tethers that couples a planar proximalelement of the gastrointestinal implant in a stomach with a distalelement of the gastrointestinal implant in an intestine; with acatheter, removing the planar proximal element proximally out of thestomach through a mouth; and with a grasper on a distal end of thecatheter, grasping a drawstring to remove the distal element proximallyout of the intestine, though the stomach and out of the mouth. Theplanar proximal element may be removed through an overtube. The distalelement may be collapsed radially into a retrieval hood. The proximalelement may also be collapsed in a retrieval hood for removal.

In accordance with an embodiment of the invention, there is provided amethod of treatment. The method comprises providing a gastrointestinalimplant device set forth herein, and securing the device across thepylorus of a patient. Chyme may be channeled from the stomach into anunsupported, thin-walled sleeve extending into the intestine from thegastrointestinal implant device. For example, a sleeve such as those setforth in U.S. Pat. No. 7,682,330 (the entire disclsoure of which ishereby incorporated herein by reference) may be used. Further, a flow ofchyme from the stomach into the intestine may be restricted with arestrictor coupled to the gastrointestinal implant device. For example,a restrictor such as those set forth in U.S. Pat. No. 7,771,382 (theentire disclsoure of which is hereby incorporated herein by reference)may be used.

The teachings of all patents, published applications and referencescited herein are incorporated by reference in their entirety.

While this invention has been particularly shown and described withreferences to example embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the scope of the inventionencompassed by the appended claims.

What is claimed is:
 1. A method of removing a gastrointestinal implant,the method comprising: severing one or more tethers that couples aplanar proximal element of the gastrointestinal implant in a stomachwith a distal element of the gastrointestinal implant in an intestine;with a catheter, removing the planar proximal element proximally out ofthe stomach through a mouth; and with a grasper on a distal end of thecatheter, grasping a drawstring to remove the distal element proximallyout of the intestine, though the stomach and out of the mouth.
 2. Themethod of claim 1, wherein removing the planar proximal elementcomprises passing the planar proximal element through an overtube. 3.The method of claim 1, wherein removing the distal element comprisescollapsing the distal element radially into a retrieval hood.